Houdini 21.0 Nodes Copernicus nodes

Grunge Birch Bark Copernicus node

Generates a pattern resembling the bark of a birch tree.

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Since 21.0

This node creates a pattern of layered noises that resemble birch bark . The Birch Bark parameters control the appearance of the base noise, lenticels , and cracks that make up the pattern. Horizontal lines across the pattern represent the lenticels and vertical lines represent the cracks. For example, configure the pattern so the bark has multiple horizontal slashes (pores).

Use this node as a building block for more intricate textures. For example, use this node to create birch canoes or tinder in fires.

Parameters

Range

Amplitude

The amount by which to multiply the pixel value (originally in the 0 to 1 range). The node applies this before the Center adjustment.

Values in the generated layer cover the range from C-A to C+A, where C is Center and A is Amplitude.

Note

Layers can store negative numbers and values above 1, so this may result in out-of-bounds values. Use Post Processing options to clamp the output.

Center

The center of the output pixel values, applied as an offset.

Values in the generated layer cover the range from C-A to C+A, where C is Center and A is Amplitude.

Note

Layers can store negative numbers and values above 1, so this may result in out-of-bounds values. Use Post Processing options to clamp the output.

Mask Contrast

The amount of contrast to apply to the pixel values before the Amplitude and Center parameters. You can use this parameter to make the values more extreme without exceeding the 0 to 1 range.

Pattern

Element Size

The size (in image coordinates) of the basic element of the generated pattern. You can turn on the Per-Component Controls button to adjust this further using the Element Scale parameter.

Element Scale

When the Per-Component Controls button is on, this is the per-axis scaling of the element size.

Offset

The amount to offset the entire pattern in image coordinates.

Tile Size

The size of a single tile of the pattern. The pattern periodically repeats in this size. The size is in image coordinates, so the default is for the entire default canonical image. If you have a non-square image, this should match the aspect ratio.

Birch Bark

Base Coverage

The amount to apply the base (internal) noise, which creates cellular shapes in the pattern. Higher values apply more of the noise, which decreases the size of the cells. Lower values apply less of the noise, which increases the size of the cells.

Base Sharpness

The severity of the base (internal) noise application. Higher values sharpen the edges of the cells and harshen the application of the noise. Lower values blur the edges of the cells and smooth the application of the noise.

Lenticels

The visibility of the lenticels (horizontal lines) in the bark. Higher values brighten and expand the lines so they cover more of the bark. Lower values fade and compress the lines until they disappear.

Lenticel Size

The size of the lenticels (horizontal lines) in the bark. Higher values zoom in on the lines so each line covers more of the pattern, which decreases the overall amount of lenticels. Lower values zoom out on the lines so each line covers less of the pattern, which increases the overall amount of lenticels.

Cracks

The visibility of the cracks (vertical lines) in the bark. Higher values brighten and reveal the lines so they stand out more from the bark. Lower values fade and hide the lines until they disappear.

Crack Size

The size of the cracks (vertical lines) in the bark. Higher values zoom in on the lines so each line covers more of the pattern, which decreases the overall amount of cracks. Lower values zoom out on the lines so each line covers less of the pattern, which increases the overall amount of cracks.

Post Processing

Note

The node applies the post-processing operations in the order they're listed.

Fold

Sets the noise values to the absolute value. For example, a pixel value of -2 becomes 2.

Note

This parameter doesn’t impact the output when there’s only positive values.

Complement

Sets the pixel value x to 1 - x.

Note

This method works for values in the 0 to 1 range. For images outside of this range, using Complement results in negative or out of range values.

Bias

The amount to pull the medium grey values (around 0.5) towards zero (if Bias is less than 1) or one (if Bias is greater than 1). A bias value of 0.5 doesn’t affect the values.

Gain

The amount to pull the medium grey values (around 0.5) together, while values around 0 and 1 are pulled apart. A gain value of 0.5 doesn’t affect the noise values.

Gamma

The overall gamma of the generated noise. Values greater than 1 increase the range of values in originally bright areas, which darkens the noise. Values less than 1 stretch out the range of values for originally dark areas, which increases the overall brightness of the noise.

Contrast

The amount to expand or shrink the overall range of tonal values. Each noise value is pushed towards (if Contrast is less than 1) or away from (if Contrast is greater than 1) medium grey values (around 0.5).

Note

This is not the same as Noise Contrast, which appears in some noise nodes and applies contrast during the noise function.

Clamp Minimum

Clamps values below the specified threshold.

Clamp Maximum

Clamps values exceeding the specified threshold.

Inputs

size_ref

A representative layer that determines the size of the output image and controls the metadata.

Outputs

grunge

The generated birch bark pattern.

See also

Copernicus nodes